Snowmobiles and other vehicles are commonly transported when loaded onto a carrier, such as when loaded in the bed of a pick-up truck. Problems with this approach to snowmobile transport arise due to the weight of the snowmobile and the difficulty inherent in turning snowmobiles around in the limited space available in the truck bed. In order to drive a snowmobile both on and off a truck bed, the snowmobile must be rotated roughly 180.degree. while in the truck bed, unless the snowmobile has a reverse gear, adding considerably to the weight and cost of the snowmobile. In practice, it is prohibitively difficult to turn a snowmobile around in a truck bed, and it is necessary to manually load or unload the snowmobile instead. Thus, if the snowmobile is driven onto the truck, then the snowmobile faces forward and must be manually unloaded. If the snowmobile is driven off the truck, then the snowmobile must have been facing backwards in the truck bed and must previously have been manually loaded. Consequently, the snowmobile must either be manually loaded or manually unloaded from the carrier, resulting in considerable inconvenience, loss of time, and the potential for injury that not unexpectedly arises from trying to move a five hundred pound machine. Such manual loading or unloading is particularly difficult in the case of a snowmobile due to the fact that the skis of the snowmobile are designed to slide forwards, and tend to steer sideways when pulled backwards.
Prior snowmobile transport apparatus has been devised to address the above noted problems. For example, U.S. Pat. No. 5,393,191 (Alexander) discloses a snowmobile-transporting device for mounting in a pick-up truck. The snowmobile-transporting device includes a snowmobile-carrying platform which supports the snowmobile. The snowmobile-carrying platform is pivotally mounted on a support frame so that the snowmobile can be rotated in the truck bed. In use, the support frame is mounted in the bed of a pick-up truck, and enables snowmobiles to be driven on and off the snowmobile transporting device on the pick-up truck.
A number of problems with the device disclosed by Alexander arise from the need to prevent unwanted rotation of the snowmobile-carrying platform and the snowmobile. It is particularly important to prevent such unwanted rotation when the pick-up truck is in motion, and when the snowmobile is being loaded or unloaded. Accordingly, the snowmobile-transporting device disclosed by Alexander provides a locking mechanism comprising brackets 43 and pins 46. In order to prevent movement of the snowmobile-carrying platform relative to the support frame, the pins are inserted into the back brackets. Unfortunately, due to the cold temperatures in which the snowmobile-carrying device is likely to be used, the pins are susceptible to becoming stuck in the brackets due to icing. Alternatively, the brackets into which the pins fit may ice over so that the pins cannot be inserted. The cold temperatures may also adversely affect the fine-motor coordination of the user of the snowmobile-carrying device, making it difficult for such user to remove and insert the pins, which may possibly be dropped and lost in the snow.
An optimal solution to the problem of what locking mechanism to use to prevent unwanted rotation of a rotatable deck on which a snowmobile is mounted, would include the following features:
(1) The mechanism should be easy to use in extremely cold temperatures, in that it should not require a great deal of fine-motor dexterity and thereby require users to remove their gloves or mitts. PA0 (2) In order to minimize the number of parts required the mechanism should preferably serve some other useful purpose in addition to locking the rotatable deck against rotation. PA0 (3) The locking mechanism should reliably prevent rotation of the rotatable deck. PA0 (4) The locking mechanism should resist becoming stuck due to icing.